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Community and Q&A

Insulating exterior block wall

EddieH | Posted in Energy Efficiency and Durability on

I’m looking at insulating the exterior cinder block walls of my home. Its located in the low desert in Arizona climate zone 2B. I already insulated the attic with blown insulation to the top of the trusses/rafters = about r-13 and batt insulation r-30 on top of that about two years ago. I’m ready to tackle the next phase in making the house more energy efficient. For the cinder block walls, the only insulation they have is a 1/2 inch foam board insulation on most of the interior walls. I am considering using rigid foam insulation with a stucco like finish. The two main products I’ve been looking at InSoFast exterior insulation and Tuff II finish. Any recommendations will be greatly appreciated. Price and ease of installation are a plus.

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  1. walta100 | | #1

    Given your climate and the high cost for adding wall insulation improving from the current R5 makes it hard to see a return on this investment in dollar.

    Have you maxed out your homes photovoltaic possibility’s?


  2. EddieH | | #2

    I rent my roof to the electric company, it's mostly over my garage. It just isn't worth me installing solar. I'm currently on the lowest tier and no time of use. If I install solar I'll go on the highest tier and with time of use. I've done a fair amount of research and it just doesn't work. My average use is less than 600kWh per month most of it used in jun, jul, and aug. Solar systems degrade over time, with a 20+ year life span, the inverters 10-12 years. If I over produce electricity it doesn't pay off because the only pay pennies on the dollar. It's not a one for one exchange. Batteries are very expensive and typically never pay for themselves even if I overproduce and don't use the grids electricity. They degrade overtime as well and will need to be replace.
    By upgrading my insulation it can last a lifetime if done correctly. Installing solar is like "stealing from Peter to pay Paul".

  3. EddieH | | #3

    Can any experts please weigh in?

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